Axillary Lymph Nodes and Breast Cancer

Lymph node of the armpits are central to the investigation

Mammography
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Axilla is a medical term used to describe your armpit. Within the axilla are lymph nodes that filter toxins and disease-causing microorganisms from the body. When breast cancer occurs, these axillary nodes can begin to swell as they filter cancer cells and try to neutralize them. Because of their proximity to the breast, axillary lymph nodes are one of the first sites doctors will examine when diagnosing breast cancer.

The Function of Axillary Nodes

The lymph nodes are part of the lymphatic system, comprised of lymph fluid, lymphatic vessels, and lymph nodes, as well as the spleen, tonsils, and adenoid. Lymph nodes are clusters of tiny organs that store white blood cells, called lymphocytes, that help fight infections and disease.

If breast cancer is suspected, doctors will often examine the armpit to see if the axillary nodes are swollen. Around 75% of lymph fluid from the breasts drains into the axillary lymph nodes, making them important in the diagnosis of breast cancer.

If blood and imaging tests suggest cancer, axillary nodes may be surgically removed to see if cancer is present. This is referred to as an axillary node biopsy. The biopsy can help your oncologist determine if cancer is present and begin the process of staging the disease.

Axillary Node Biopsy

A common procedure used to determine the presence of cancer is called a sentinel node biopsy. The term "sentinel" refers to the first point in which disease occurs. A sentinel is usually performed on an outpatient basis in a hospital or specialized surgery center.

The process starts with an injectable dye that helps the doctor locate the appropriate nodes to remove. The first node that absorbs the dye is called the sentinel node; it is the first in the string of lymph nodes into which cancer cells are filtered. Because it is the first, it is more likely to deliver a more accurate result than one that is further down the pipeline.

That node is sent off to a lab to see if cancer cells are in the node. If the sentinel node does not have cancer, it is unlikely that your other nodes will have it either. In that case, further surgery is not necessary.

Axillary Dissection

 If cancer is present, an axillary dissection will be performed to remove additional lymph nodes. The axillary dissection will determine how many lymph nodes have cancer. This will help determine how much treatment is needed to bring the cancer into a state of sustained remission.

For women with invasive breast cancer, this is usually done at the same time as a mastectomy. During a typical axillary dissection, between two and around twenty nodes on average may be removed. The number of nodes is one of the key criteria for determining if the cancer is early (stage 1 to 2a) or more advanced (stage 2b to 4).

During the axillary dissection, you will be put under general anesthesia with your arm lifted over your head. It's a relatively quick and painless procedure. 

An axillary dissection may cause side effects. Chief among them is lymphedema, the swelling of the arm, hand, breast, or torso due to the disruption of lymph vessels. The approximate risk of lymphedema following axillary dissection is 14%. This can increase to 33% if radiation therapy is used.

There may also be a loss of sensation in the breast or axilla, limited arm mobility, and muscle weakness. Most of these symptoms are temporary and will improve over time. Women are typically asked to avoid lifting heavy objects during recovery. Many women experience no side effects from axillary dissection.

During recovery, it is important to let your doctor know if you experience abnormal symptoms, such as high fever, a pus-like discharge, or increasing pain, swelling, and redness.

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  1. Vicente JS, Grande ML, Barquero CD, et al. Bilateral axillary and internal mammary drainage in breast cancer without prior surgery during sentinel node mapping. Indian J Nucl Med. 2011;26(4):205-7. doi:10.4103/0972-3919.106716

  2. Somner JE, Dixon JM, Thomas JS. Node retrieval in axillary lymph node dissections: recommendations for minimum numbers to be confident about node negative statusJ Clin Pathol. 2004;57(8):845–848. doi:10.1136/jcp.2003.015560

  3. Johnson AR, Kimball S, Epstein S, et al. Lymphedema incidence after axillary lymph node dissection: quantifying the impact of radiation and the lymphatic microsurgical preventive healing approach. Ann Plast Surg. 2019;82(4S Suppl 3):S234-41. doi:10.1097/SAP.0000000000001864